Inertia operated automatic shotgun choke



Nov. 10, 1964 w. B. EVANS INERTIA OFERATED AUTOMATIC sHoTGuN cHoxE 2 Sheets-Sheet l Filed March 11, 1963 INVENTOR. WALTON B. EVANS 2 Sheets-Sheet 2 w. B. EVANS l INVENTOR WALTO N B. EVA N s INERTIA OFEIRATED AUTOMATIC SHOTGUN CHOKE Nov. 10, 1964 Filed March 11, 1963 fda@ United States Patent O 3,156,061 NERTIA PERATED AUTMATC SHTGUN CHKE Walton B. Evans, Newalla, Ghia. (420 S. Highland Ave., Midwest City, Ghia.) Filed Mar. ll, 1963, Ser. No. 264,353 4 Claims. (Cl. i2---79) The present invention relates to improvements in shotguns and more particularly to devices used with Shotguns usually referred to as chokes which are intended to constrict the area of the shot pattern of the gun.

Shotgun cholzes are not new but most of those presently available permanently restrict the shot pattern of the gun or, if of the adjustable type, the choke is manually operated before or after tiring the gun.

It is highly desirable to have a choke of a type wherein the shot pattern will not be restricted for the iirst shot and wherein the choke will be automatically and rapidly operated to restrict the shot pattern and increase the range of killing power of the gun before the next shot is lired. if the choke must be manually operated for the second shot, the game, such as a bird, will be out of range before the second shot can be tired,

It is, therefore, the principal object of the instant invention to provide a choke for a shotgun which will be operated by the recoil of the gun to actuate an inertia body and reduce the shot pattern of lthe gun when the first shot is iired.

Another object is the provision of an automatic shotgun choke which may be moved manually and locked in either full open or choke position,

Still another object is to provide a shotgun choke of this class which does not rely on gas pressure from a tired shell for its operation.

A further object is the provision of a device of this class which, when installed, does not lengthen or form an extension of the gun bore.

Other objects are simplicity and economy of construction, eihciency and dependability of operation and adaptability for connection with any shotgun of the single barrel multiple shot type.

The present invention accomplishes these and other objects by connecting a tubular housing to a shot gun barrel rearwardly of a forward contractile section. A tubular inertia body slidably surrounds the barrel forwardly of the housing while a locking means, slidably carried by the housing and removably engageable there with, holds the body in gun barrel full open or choked position.

Other objects Will be apparent from the following description when taken in conjunction with the accompanying two sheets of drawings, wherein:

FIGURE l is an elevational View ofthe device installed on a fragment of a gun barrel;

FIGURE 2 is a vertical cross-sectional view taken substantially along the line 2-2 of FIG. 1 showing the gun barrel in full open position;

FIGURE 3 is a View similar to FIG. 2 showing the device in choke position;

FlGURES i and 5 are vertical cross-sectional views taken substantially along the respective lines 4-4 and 5*-5 of FIG. 3; and, Y

FIGURE 6 is a perspective View of a portion of the device with parts broken away for clarity.

Like characters of reference designate like parts in those figures of the drawings in which they occur.

In the drawings:

The reference numeral lill indicates the forward end portion of a gun barrel having a plurality of slits or slots 12 extending longitudinally rearward from the forward end of the barrel to provide a plurality of gun barrel "ice tongues 14. The periphery of a forward portion of the barrel, defined by the tongues inl, is ground off or tapered, as at i3, to form a thinner wall for the barrel. The slots 12 are relatively narrow so that shot from a shotgun shell will not become lodged therein when the barrel is in full open position. The slots i2 and tongues ifi form a contractile section for the forward end of the barrel capable of iiexing inwardly to reduce the internal diameter of the forward end portion of the barrel.

The numeral 2lb indicates the choke, as a whole, which loosely surrounds and is inline with the forward end of the barrel l) and extends, when in full open position, from a point rearwardly of the slots 12 forwardly slightly beyond the forward end of the tongues i4 (FIG. 2). A tubular housing 22 is secured to the gun barrel itl rearwardly of the rearwardmost end of the slots l2. The housing 22 includes an annular ange 24. A tubular inertia body 26 surrounds the contractile section of the gun barrel. The body 26 is characterized by a forwardly tapered or converging inner wall portion Ztl which slidably contacts the tapered or beveled surface i3 of the tongues id. The rearward end of the body 26 is characterized by an outstanding annular iiange 3th diametrically slightly smaller than the housing flange 24. An annular ring 32 surrounds the body 26 forwardly of its flange 3l?. A tubular sleeve 34 is connected at its respective ends to the periphery of the housing iange 24 and ring 32. A helical strong expansion spring 36 surrounds the body 26 within the sleeve 34 and contacts, at its respective ends, the adjacent surface of the body liange 36 and the ring 32. An activating sleeve or handle 38 loosely surrounds the gun barrel rearwardly of the housing 22. The forward end of the handle is counterbored, as at dit, for receiving one end of a plurality, preferably four, circumferentially spaced-apart elongated transversely arcuate tangs 4t2. The tangs project forwardly of the handle through a like plurality of cooperating circumferentially spaced slots 44 formed in the housing iiange 24 and are connected at their respective forward ends to the adjacent face or surface of the body fiange 39. Each of the tangs 42 is provided, on a similar side, with a notch or recess 46 which is releasably engageable with the wall forming the respective end of the respective housing slot 44% by rotation of the handle. Adjacent their forward ends the tangs 42 are each provided with a second notch ad on their respective longitudinal side opposite the recesses i6 for engagement with the opposite end of the respective housing slot 44 in the flange 2d by rearward movement and rotation of the handle in an opposite direction. The notches d are characterized by a forwardly inclined surface Sil for the purposes more fully explained hereinbelow.

An inertia throw ring 52 loosely surorunds the tangs and gun barrel between the housing 22 and body 26 within the sleeve 3ft- The throw ring 52 is provided with a series, preferably four, outstanding pins 53 slidably dis posed in a like plurality of suitable camnring slots 56 Vformed in the sleeve 34 which rotate the throw ring in a camming action to revolve the handle 38 and inertia body 26 around the barrel lil in a manner more fully described hereinbelow.

The throw ring 52 is similarly provided with a plurality of slots 5S which receive the tangs 42 for a longitudinal sliding movement of the rangs therethrough.

A cylindrical inertia body or slide Si is interposed between the throw ring 52 and body iiange 30. The slide 51 loosely surorunds the tangs i2 and its outside diameter is less than the inside diameter of the sleeve 34. The forward end of the slide 5l is counterbored, as at 54, for receiving a spring 55 which is interposed between the inner limit of the counterbore 54 and the adjacent surface of the body dange Sil around the tangs 3 42. As shown in FIGS. 2 and 3, the respective ends of the spring 55 are positioned in cooperating sockets respectively formed in the body flange 30 and slide 51.

As seen by a comparison of FIGS. 4 and 5, the housing slots 44 permit a limited amount of rotative or circumferential movement of the 4tangs 42 with respect to the housing 22 while the throw ring slots 53 are substantially equal to the transverse cross section area of the tangs. Thus when the throw ring 52 is rotated by the pins 53 in response to movement of the throw ring toward the housing 22 the throw ring slots slidably contact the tangs 42 and rotate the latter, the handle 3S and body 26 circumferentially of the barrel 10.

In operation the device 20 is connected to a gun barrel as disclosed hereinabove. The choke is normally in full open position, as shown by FIG. 2, wherein the ltang locking notches 46 are engaged with the slots 44 in the housing flange. When the gun is fired the recoil moves the housing 22, ring 32 and sleeve 34 rearwardly which causes the inertia slide 51 to compress its spring S5. The spring 55 then moves the slide 51 rearwardly, in a snapping action, to contact the throw ring 52. This moves the throw ring 52 toward the housing 22 wherein the pins 53 are cammed by the sleeve slots 56 to rotate the throw ring which in turn rotates the handle 38 and tangs 42 so that the rearward notches 46 in the tangs are released from contact with the slots 44 in the housing flange 24. This permits expansion of the heavy spring 36 which forces the body flange 30 toward the housing fiange 24. This forces the throw ring pins 53 further rearwardly in the sleeve cam slots 56 which revolves the tangs 42 and connected components so that the forward tang notches 48 engage with the housing slots 44 to lock the device in choke position. The forward taper 50 of the notches 48 lengthens the effective width of the notches to insure the engagement of the latter with the housing fiange 24. Movement of the inertia body 26 toward the housing 22 constricts the diameter of the barrel 10 by the inward flexing and constriction of the barrel tongues 14 (FIG. 3). When it is desired to again position the choke in full open position, the handle 38 is rotated to release the notches 48 from contact with the housing fianges 24 and then manually pushed forwardly along the barrel 10 and rotated in the opposite direction to engage the tang recesses 46 with the housing ange 24.

Obviously the invention is susceptible to some change or alteration without defeating its practicability, and I therefore do not wish to be confined to the preferred embodiment shown in the drawings and described herein, further that I am limited by the scope of the appended claims.

I claim:

1. An automatic choke in combination with a shotgun having a barrel and having circumferentially spaced slots extending longitudinally rearward from the forward end of said barrel forming a resilient contractile section, comprising:

a tubular housing secured to said barrel rearwardly of the contractile section, said housing having an annular flange perpendicular to the axis of said barrel, said flange having a plurality of circumferentially spaced slots therethrough;

a cylindrical first inertia body slidably surrounding said barrel forwardly of said housing and operable by movement rearwardly of the forward end of the barrel to constrict the contractile section of the latter and vary the pattern of shot fired therethrough;

a ring slidably surrounding said first inertia body intermediate its ends;

a sleeve extending between and connected at its respective ends to the periphery of said housing flange and said ring;

a resilient member around said first inertia body within said sleeve normally urging said first inertia body rearwardly of the forward end of said barrel;

a handle surrounding said barrel rearwardly of said housing;

a plurality ofr circumferentially spaced tangs interconnecting said first inertia body and said handle, said tangs slidably projecting longitudinally through the slots in YsaidY housing fiange,-each of said-tangs hav-- ing a first recess in one edge thereof engaging said housing flange; and

means interposed between said housing fiange and said first inertia body and actuated by the recoil of said shot gun for rotating said tangs around a portion of the barrel.

2. Structure as specified in claim l in which said means includes:

a throw ring loosely surrounding said barrel between said housing and said first inertia body within said sleeve, said sleeve having a plurality of circumferentially spaced-apart slots through its wall characterized by arcuate edges extending toward the forward end of said sleeve from said housing flange, said throw ring having a plurality of transverse slots slidably receiving said tangs;

pins secured to the periphery of said throw ring and projecting outwardly through the slo-ts in said sleeve;

a second inertia body loosely interposed between said throw ring and said first inertia body around said tangs, said second inertia body having a counterbore in its end projecting toward the forward end of said barrel; and,

a spring interposed between said first inertia body and the inner end of the counterbore in said second inertia body around said tangs,

whereby said pins are cammed by the arcuate edges of said slots in said sleeve and rotate saidthrow ring during its movement rearwardly of the forward end of said barrel in response to the recoil of said shotgun, and

whereby the rotative movement of said throw ring rotates said tangs around a circumferential portion of said barrel -to release the first recess of each said tang from contact with the respective wall surface in said housing fiange forming the tang receiving slot.

3. Structure as specifiedin claim 2 in which said spring is connected at its respective ends to said first and second inertia bodies.

4. Structure as specified in claim 3 in which said tangs are provided with a second recess on each of its longitudinal sides opposite the first said recess, each said second recess being of a size to engage said flange of said housing in locking relation in response to the movement of said first inertia body rearwardly of the forward end of the barrel.

References Cited by the Examiner UNITED STATES PATENTS 2,759,286 8/56 Moore 42-79 2,861,376 11/58 Denaux 42-79 2,867,932 1/ 59 Keightley 42-79 BENJAMIN A. BORCHELT, Primary Examiner. 

1. AN AUTOMATIC CHOKE IN COMBINATION WITH A SHOTGUN HAVING A BARREL AND HAVING CIRCUMFERENTIALLY SPACED SLOTS EXTENDING LONGITUDINALLY REARWARD FROM THE FORWARD END OF SAID BARREL FORMING A RESILIENT CONTRACTILE SECTION, COMPRISING: A TUBULAR HOUSING SECURED TO SAID BARREL REARWARDLY OF THE CONTRACTILE SECTION, SAID HOUSING HAVING AN ANNULAR FLANGE PERPENDICULAR TO THE AXIS OF SAID BARREL, SAID FLANGE HAVING A PLURALITY OF CIRCUMFERENTIALLY SPACED SLOTS THERETHROUGH; A CYLINDRICAL FIRST INERTIA BODY SLIDABLY SURROUNDING SAID BARREL FORWARDLY OF SAID HOUSING AND OPERABLE BY MOVEMENT REARWARDLY OF THE FORWARD END OF THE BARREL TO CONSTRICT THE CONTRACTILE SECTION OF THE LATTER AND VARY THE PATTERN OF SHOT FIRED THERETHROUGH; A RING SLIDABLY SURROUNDING SAID FIRST INERTIA BODY INTERMEDIATE ITS ENDS; A SLEEVE EXTENDING BETWEEN AND CONNECTED AT ITS RESPECTIVE ENDS TO THE PERIPHERY OF SAID HOUSING FLANGE AND SAID RING; A RESILIENT MEMBER AROUND SAID FIRST INERTIA BODY WITHIN SAID SLEEVE NORMALLY URGING SAID FIRST INERTIA BODY REARWARDLY OF THE FORWARD END OF SAID BARREL; A HANDLE SURROUNDING SAID BARREL REARWARDLY OF SAID HOUSING; A PLURALITY OF CIRCUMFERENTIALLY SPACED TANGS INTERCONNECTING SAID FIRST INERTIA BODY AND SAID HANDLE, SAID TANGS SLIDABLY PROJECTING LONGITUDINALLY THROUGH THE SLOTS IN SAID HOUSING FLANGE, EACH OF SAID TANGS HAVING A FIRST RECESS IN ONE EDGE THEREOF ENGAGING SAID HOUSING FLANGE; AND MEANS INTERPOSED BETWEEN SAID HOUSING FLANGE AND SAID FIRST INERTIA BODY AND ACTUATED BY THE RECOIL OF SAID SHOT GUN FOR ROTATING SAID TANGS AROUND A PORTION OF THE BARREL. 